This text addresses the problems of evaluating the patient with exercise intolerance, with physiology, pathophysiology and differential diagnosis as frames of reference. It contains a wide range of clinical examples, as well as providing the justification and tools for using exercise testing as part of cardiorespiratory examination. Thus, it attempts to span the field of exercise, from basic concepts in exercise physiology to the practical aspects of delivering a meaningful report for the medical record that specifies the mechanism and degree of a subject's exercise limitation. The work also provides a more complete understanding of the disease process and its effect on exercise performance. It gives the conceptual basis for analyzing how cardiovascular, respiratory and other disorders limit exercise performance. Appendices cover symbols and abbreviations; devices and systems for collecting and analyzing physiological data; calculations - formulae and examples; preparation for the exercise test; and tables and nomogram.